1. Field of the Invention
This invention relates to a method for detecting hydrocarbons in water and, in particular, to a method comprising extracting the hydrocarbons from the water using an absorbent material and a water-miscible solvent.
It is now well-accepted that corporations and individuals have a legal duty to protect the environment, including water, against contamination by the inadvertent release of oil or other hydrocarbons, and that remedial measures must be taken should such accidents occur. Various tests have been developed to enable investigators to detect the presence of hydrocarbons in water to help identify releases from leaking storage tanks and other sources of contamination.
2. Related Art
U.S. Pat. No. 3,700,409 to Zall, dated Oct. 24, 1972, discloses a method of detecting hydrocarbon contaminants in aqueous solutions. The method involves passing an aqueous sample through fiberglass filter paper and then contacting the filter paper with a small amount of chromic-sulfuric acid. A resultant bluish-green color indicates the presence of hydrocarbons in the aqueous sample.
U.S. Pat. No. 4,146,799 to Pitt et al, dated Mar. 27, 1979, discloses an apparatus for detecting oil in water employing a scatter cell, an infrared laser beam connected to the cell via a fiber optic interface and one or more light scattering detectors (i.e., photocells) all individually connected to the cell via fiber optic interfaces. The scatter cell is dimensioned and configured so that a first photocell is arranged in a direct line with an infrared laser beam and at least one or more photocells are arranged at a relatively small angle (e.g., 20.degree.) to the light source. Compensation circuitry may be employed to nullify small perturbations caused by rust particles.
U.S. Pat. No. 5,355,736 to Skogley, dated Oct. 18, 1994, discloses an apparatus and process for collecting and preparing test samples for analysis of diffused ions therein. The diffused ions are adsorbed by an adsorbent material by contacting the sample with the absorbent material for a substantial amount of time. The ions are then recovered by contacting the adsorbent material with a strong acid or base or a salt solution for later quantitative analysis.